자해 청소년의 퇴원 후 일상생활 적응 과정

황대원 ( Hwang Dae Won ),한금선 ( Han Kuem Sun ) 한국정신간호학회 2023 정신간호학회지 Vol.32 No.4

Purpose: The purpose of this study was to understand the process of adapting to daily life after discharge of self-injury adolescents and to develop a substantive theory that can explain their experiences. Methods: Data collection and analysis were conducted through interviews with 9 participants who returned to their daily life after discharge, and data analysis was conducted according to the grounded theory approach. Results: As a result of the analysis, a total of 31 concepts and 9 categories were derived, and were classified into the areas of conditions, actions-interactions, and consequences according to the grounded theory paradigm. As a core category that can explain all these concepts and categories, ‘balance oneself in a precarious daily life’ was derived. Conclusion: In this study, a theory in which this process was composed in the order of return stage, crisis stage, and transformative stage, was presented. Finally, the discussions and suggestions of this study based on these results were described.

고전압 GaN 쇼트키 장벽 다이오드의 완충층 누설전류 분석

황대원(Dae Won Hwang),하민우(Min-Woo Ha),노정현(Cheong Hyun Roh),박정호(Jung Ho Park),한철구(Cheol-Koo Hahn) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.2

본 논문에서 실리콘 기판 위에 성장된 GaN 에피탁시를 활용하여 고전압 쇼트키 장벽 다이오드를 제작하였으며, 금속-반도체 접합의 열처리 조건에 따른 GaN 완충층 (buffer layer) 누설전류와 제작된 다이오드의 전기적 특성 변화를 연구하였다. Ti/Al/Mo/Au 오믹 접합과 Ni/Au 쇼트키 접합이 제작된 소자에 설계 및 제작되었다. 메사를 관통하는 GaN 완충층의 누설전류를 측정하기 위하여 테스트 구조가 제안되었으며 제작하였다. 700℃에서 열처리한 경우 100 V 전압에서 측정된 완충층의 누설전류는 87 ㎁이며, 이는 800℃에서 열처리한 경우의 완충층의 누설전류인 780 ㎁보다 적었다. GaN 쇼트키 장벽 다이오드의 누설전류 메커니즘을 분석하기 위해서 Auger 전자 분광학 (Auger electron spectroscopy) 측정을 통해 GaN 내부로 확산되는 Au, Ti, Mo, O 성분들이 완충층 누설전류 증가에 기여함을 확인했다. 금속-반도체 접합의 열처리를 통해 GaN 쇼트키 장벽 다이오드의 누설전류를 성공적으로 감소시켰으며 높은 항복전압을 구현하였다. We have fabricated GaN Schottky barrier diode (SBD) for high-voltage applications on Si substrate. The leakage current and the electrical characteristics of GaN SBD are investigated by annealing metal-semiconductor junctions. Ohmic junctions of Ti/Al/Mo/Au and Schottky junctions of Ni/Au are used in the fabrication. A test structure is proposed to measured buffer leakage current through a mesa structure. When annealing temperature is increased from 700℃ to 800℃, measured buffer leakage current is also increased from 87 ㎁ to 780 ㎁ at the width of 100 ㎛. The diffusion of Au, Ti, Mo, O into GaN buffer layer increases the leakage current and that is verified by Auger electron spectroscopy. Experimental results show that the low leakage current and the high breakdown voltage of GaN SBD are achieved by annealing metal-semiconductor junctions.

Convolutional Neural Network based Rating Prediction of Travel Destinations in Social Media

Dae Won Hwang(황대원),Min Gu Kim(김민구),Dong Jin Yook(육동진),Il Hong Suh(서일홍) 대한전기학회 2017 정보 및 제어 심포지엄 논문집 Vol.2017 No.10

심장 점액종의 임상적 고찰

황의석(Eui Seock Hwang),김용석(Yong Seok Kim),최진오(Jin Oh Choi),채인호(In Ho Chae),손대원(Dae Won Sohn),김철호(Cheol Ho Kim),오병희(Byung Heui Oh),이명묵(Myoung Mook Lee),박영배(Young Bae Park),최윤식(Yun Shik Choi),이영우(Young Wo 대한내과학회 2002 대한내과학회지 Vol.62 No.1

N/A Background: Cardiac myxoma is uncommon, even though accounts for 50% of primary cardiac tumor, histologically benign disease but may be lethal because of its strategic position. It has diverse clinical manifestations mimicking various diseases, which can be described under the three headings: constitutional, obstructive and embolic and the diagnosis can be easily missed unless clinician has high index of suspicion. A correct diagnosis is made before operation with the development of echocardiography. We reviewed our clinical experience in diagnosis and management of 21 cases of myxomas from 1985 to 2000. Methods: There were 4 males (19%) and 17 females (81%). Their ages ranged from 17 to 66 years (mean 42.2 years). All the patient`s medical records on their clinical features, laboratory findings, chest X-rays, electrocardiograms, echocardiographic findings, operative findings and post operative follow-up were reviewed. Results: Seventeen cases (81%) of the myxomas originated in left atrium and four (19%) in right atrium. Most common symptom was that of intracardiac obstruction such as dyspnea or dyspnea on exertion (62%). Fatigue which accounted for most of the constitutional symptom found in 38% of the 21 patients while embolism accounted for 38%. In all patients, echocardiography was used for diagnosis and the diagnostic accuracy of echocardiography was 100%. All patient s received surgical treatment and immediate postoperative complications occurred in seven patients (33%). Among them, serious complications were found in two cases and one expired due to congestive heart failure. Follow-up duration ranged from 2 months to 15 year s. There was no recurrence or other problem in all patient s during the follow-up period. Conclusion: Although clinical suspicion is difficult due to the nonspecific presentation of myxoma, the diagnosis can be made easily with echocardiographic examination in all cases and surgical excision of myxoma may be curative with good long-term result.(Korean J Med 62:49-57, 2002)

출생 후 제대혈관 폐쇄에서의 세포고사

황경국(Kyung Kuk Hwang),김효수(Hyo Soo Kim),서정욱(Jung Uk Seo),채인호(In Ho Chae),손대원(Dae Won Sohn),오병희(Byung Hee Oh),이명묵(Myoung Mook Lee),박영배(Young Bae Park),최윤식(Yun Shik Choi),서정돈(Jung Don Seo),이영우(Young Woo L 대한내과학회 1998 대한내과학회지 Vol.55 No.6

N/A Background: The mechanism of the closure of umbilical vessels is known to be multifactorial. In order to verify that apoptosis is one of the possible closure mechanisms, we studied to identify apoptosis in umbilical vessels and evaluate its mechanism by studying apoptosis-related gene and the relationship between the pattern of apoptosis and gestational age (GA). Methods: Twelve umbilical cords of GA of 37-42 weeks were obtained immediatly (less than 10 min. for minimal ongoing external influences) after birth. The presence of apoptotic cells was demonstrated by electron microscopy (EM) and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL). Immnohistochemical staining and Western blotting were used for the analysis of the proteins of apoptosis-related gene. Results: Apoptosis of the smooth muscle cells of media and intima of umbilical vessels was identified at EM, regardless of GA from 37 to 42 weeks. The proportion of TUNEL(+) cells was 80% in intima, 40% in media, 80% in connective tissue of umbilical cord. The expressions of bax-a, bcl-Xs/L were strong in intima, in media and connective tissue, but those of bcl-2 were detected in only in connective tissue, regardless of GA in immunohistochemistry. The ratios of expressions of bax- a to bc1-2, bcl-Xs to bcl-XL, did not change with increasing GA from 37 to 42 weeks in Western blot- ting. Conclusion: Apoptosis was identified in umbilical vessels. The closure of umbilical vessels can be explained by apoptosis where the ratios of bax-a/bcl-2, bcl-Xs/ bcl-XL play an important role. The fact that there were no differences in the extent of apoptosis and the expressions of bax-a/bcl-2, bcl-Xs/bcl-XL according to GA, suggests that apoptosis of umbilical vessels is more dependent on the external stimuli during delivery than GA.

내막파열을 동반하지 않은 대동맥 박리 ( 대동맥 벽내출혈 ) 에 대한 임상적 고찰

황경국(Kyung Kuk Hwang),박대균(Dae Gyun Park),연태진(Tae Jin Yeun),조영석(Young Seok Cho),손대원(Dae Won Sohn),김효수(Hyo Soo Kim),김철호(Cheol Ho Kim),오병희(Byung Hee Oh),이명묵(Myoung Mook Lee),박영배(Young Bae Park),최윤식(Yun Sh 대한내과학회 1998 대한내과학회지 Vol.54 No.1

N/A Objectives: This study was performed to verify the incidence and prognosis of aortic dissection without intimal tear (aortic intramural hemorrhage, IMH) who took only medical treatment in special referrence to Stanford type A. Methods: We analysed the patients of IMH confirmed by TEE, CT, MRI, angiography or CT-angiography in Seoul National University Hospital between 1987 and l9%, retrospectively. Results: The diagnosis of IMH was estabilished in 20 of 143 patients(14%). Nine patients were Stanford type A, 11 patients were type B. The longitudinal extent varied between 8 and 30cm, and IMH size varied between 10 and 3mm. Surgery was performed in two of type A patients because of persistent chest pain and one of type B patients because of progressive aortic dilatation despite of medical treatment. Follow-up imaging studies (mean follow-up period of 20.0±22.0 months) were done in 10/17 patients who were treated medicaliy. Complete resolution of IMH was observed in seven cases, four of them were Stanford type A, and the mean size of IMH was 12mm(10-17mm). Partial resolution was observed in one case, Stanford type A, with the IMH size of 15mm. There was no significant change in the size of IMH in two cases. Initial mean size of IMH was 25mm. In no case, aortic rupture or death was observed during the follow up period. Conclusion: In the management of the patient with MH, same surgical indications as classic aortic dissection have been advocated based on similar prognosis. However our study showed better prognosis in IMH patients treated medically compared to the previous publications. Therefore, even in cases of proximal IMH. medical treatment should be seriously considered.

생체 신이식후 발생한 급성거부반응의 스테로이드 대량요법에 대한 반응

조원현(Won Hyun Cho),황대원(Dae Won Hwang),박철희(Choal Hee Park),이수형(Soo Hyung Lee),박성배(Sung Bae Park),김현철(Hyung Chul Kim) 대한외과학회 1993 Annals of Surgical Treatment and Research Vol.45 No.6

온도 유지시간 제어를 적용한 하이브리드 분말 압출 공정을 통한 요구 특성의 스퍼기어 제조

이경훈(Kyung Hun Lee),황대원(Dae Won Hwang),김병민(Byung Min Kim) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.8

본 연구는 압출 시 성형온도를 유지하여 Zn-22Al 합금분말의 성형성을 향상시키는 하이브리드 분말 압출 공정의 개발 및 온도 유지시간이 압출된 스퍼기어의 기계적 특성에 미치는 영향을 조사하기 위해 수행되었다. 피치원 지름 1.8mm 의 소형 스퍼기어는 압출온도 290, 300, 310℃에서 성형되었다. 볼밀시간 32h 의 Zn-22Al 합금분말을 압출온도 310℃에서 압출 시 표면 결함이 없는 소형 기어가 제조되었다. 경도분포는 기어 중심부와 치형부에서 불균일하였고 소결공정 후 내부 변형에너지의 차이로 인해 내부균열이 발생하였다. 위와 같은 문제를 해결하기 위해 온도 유지시간 제어를 이용한 하이브리드 압출 연구를 수행하였다. 압출된 스퍼기어의 평가는 압출하중, 비커스 경도 및 치수정밀도 측정을 통해 이루어졌다. 온도 유지시간 15min 에서 압출된 스퍼기어의 기계적 성질이 가장 우수하였다. In this study, a hybrid powder-extrusion process involving the control of temperature dwelling time for improving the formability of Zn-22Al powder was developed and the effect of dwelling time on the mechanical properties of a spur gear with a pitch circle having a diameter of 1.8 mm was investigated. General extrusion experiments were carried out at different temperatures such as 290, 300, and 310°C. Spur gears with good qualities and without any surface defects were obtained in the case of extrusion temperature of 310°C and ball-milling duration of 32 h. The Vickers hardness distribution was non-uniform, and after the sintering process, an internal crack was generated because of the different deformation energy between gear central part and teeth. To overcome the abovementioned problems, research on controlling the dwelling time of the extrusion temperature in the powder-extrusion process was carried out. Good-quality spur gears were obtained when the dwelling time was 15 min.

스크립트를 활용한 아바타 콘텐츠 제작 시스템

김지훈(Ji-Hoon Kim),황대원(Dae-Won Hwang),서경진(Kyoung-Chin Seo) 한국디지털콘텐츠학회 2022 한국디지털콘텐츠학회논문지 Vol.23 No.1

Due to COVID-19, the demand for non-face-to-face services has increased, and accordingly, the demand for content using animations of 3D avatars has also increased. However, 3D animation content is expensive and cannot be easily produced. In this paper, we propose a script-based animation system that can create contents using 3D avatars. We develop tools for generating voice and lip sync data from text, assigning animation clips to match lines, and organizing content scenarios. In order to combine various animations through scripts, we built an animation set made in short motion units for each body part. We developed a system that can produce avatar content that speaks and operates according to the scripts instructions by creating a script that assigns animations to lines according to the defined gesture steps. We show that avatar content can be produced efficiently through our demonstration that 3D avatar can interact with users.

기상반응에 의한 니켈 나노입자 제조 연구

장희동 ( Hee Dong Jang ),황대원 ( Dae Won Hwang ),김헌창 ( Heon Chang Kim ) 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.1